Assisted Reproductive Technologies

Although ARTs are usually performed with the gametes (i.e., sperm and eggs) of the intended parents, in some cases gametes of one of the intended parents are combined with donor gametes. Gamete donors may be friends or relatives of the intended parents, or they may be individuals who have been recruited by the ART program and paid for their services. In the latter situation, the identity of the donor is usually not disclosed to the recipients, although nonidentifying medical and personal information may be made available.

Sperm donation is used for a variety of purposes. First, it may be used when the male partner is unable to produce a sufficient amount of viable sperm. It is a far less expensive treatment for this purpose than ICSI and, because it can be used in conjunction with assisted insemination, the woman does not have to undergo the medical risks and burdens of IVF. Second, sperm donation may be used by couples at risk of transmitting certain genetic diseases. For example, if both partners are carriers of a recessive genetic disorder, such as sickle-cell disease, using sperm from a donor who is not a carrier will ensure that the resulting child is not born with the disease. Finally, sperm donation may be used by single women or lesbian couples who seek to reproduce without a male partner. Sperm donation is a simple process that involves no physical risks to the donor.

Although sperm donation has been available since the 1950s, egg donation is a relatively new procedure, available only since the early 1980s. It is used by women who are unable to produce eggs of their own or, as with sperm donation, by couples who want to avoid transmitting certain genetic diseases. Egg donation enables women to have children long after they have passed menopause; in 1997, physicians reported a successful pregnancy in a 63-year-old woman who had used egg donation (New York State Task Force on Life and the Law 1998). Unlike sperm donation, being an egg donor is time consuming and involves medical risks, primarily those associated with ovarian stimulation and egg retrieval. Donors are generally college-age women, and they are typically paid several thousand dollars for each cycle of donation.

Depending on applicable state law, some ART programs offer the option of surrogate parenting (also known as surrogacy). Surrogacy does not refer to a specific type of ART, but rather to a social arrangement in which a woman agrees to become pregnant and relinquish the child to the intended parents after birth. Surrogacy is used by couples in which the female partner is unable to gestate a pregnancy, or by single men or gay male couples who want to reproduce without a female partner. With genetic-gestational surrogacy (sometimes referred to as traditional surrogacy), the surrogate becomes pregnant by undergoing assisted insemination with the intended father's sperm. With gestational surrogacy, the intended parents create an embryo through IVF (using their own gametes, donor gametes, or a combination), and the embryo is then transferred into the surrogate to establish a pregnancy.

The ability to cryopreserve, or freeze, gametes and embryos is an important part of many ART procedures. Both sperm and embryos can be cryopreserved. Some success has been achieved with freezing unfertilized eggs, although the cryop-reservation of eggs is still considered experimental. One of the benefits of cryopreservation is that it can preserve the reproductive capacity of individuals about to undergo chemotherapy or other medical treatments that might impair their fertility. In addition, for couples undergoing IVF, the ability to cryopreserve extra embryos makes it possible to engage in additional attempts at pregnancy without having to undergo ovarian stimulation and egg retrieval each time. If couples have excess frozen embryos after they are finished with their treatment, they can keep them in storage indefinitely, destroy them, donate them to other patients, or make them available to researchers (Coleman 1999).

Some people use ARTs in order to take advantage of pre-implantation genetic diagnosis (PIGD). With PIGD, physicians create embryos through IVF, remove one or more cells from each embryo (a process that does not harm the embryos), and then perform genetic testing on the removed cells. PIGD enables individuals at risk of transmitting serious genetic disorders to select for implantation only those embryos found not to be affected. It also permits prospective parents to determine the sex of their children by transferring embryos of only one sex. In addition to PIGD, individuals who want to increase the likelihood of having a child of a particular sex can do so before conception through the use of sperm-sorting technologies, although, unlike PIGD, these techniques cannot guarantee the birth of a child of a particular sex.

In the future, it may be possible to go beyond the process of genetic screening to affirmative genetic manipulation of embryos. Such techniques could give individuals significant control over their children's genetic makeup by enabling physicians to eliminate traits considered undesirable, or to add traits considered desirable.